Table 1

Percentages of secondary structure of salmon and squid protamines in sperm nuclei.

Salmon protamine

Squid protamine

Assignment

140 mM

140 mM

600 mM

Band cm-1

%

Band cm-1

%

Band cm-1

%

Turns

1674

16

1669

17

1669

17

Turns

1663

22

1662

20

1661

22

α-helix

1652

20

1650

40

1650

39

Random coil/flexible regions

1642

42

1640

23

1640

22

Side Chain

1609

-

1609

-

1609

-

The concentration of nuclei expressed as DNA concentration was 5 mg/ml. Band position
(cm-1) and percentage area (%) and assignment of the components were obtained after curve
fitting of the amide I band (D2O). The buffer was 10 mM Hepes plus 140 or 600 mM NaCl, pH7.0. The values were rounded
off to the nearest integer.